Electrical apparatus



Jan. 16, 1934. w.v J. 'KING Y 1,944,133

ELECTRICAL APPARATUS Filed Jan. 12, 1951 l {mourra/F v @aaa/f Pipi/R INVENTOR.

WAKE? ./T KW@ Patented Jan. 16, 19341 PATENT oFFic 1,944,138 ELECTRICAL APPARATUS Walker J. King, Elmhurst, lll., assignor, by mesne assignments, to Grigsby-Grunow Company, a

corporation of Illinois Application January 12, 1931. Serial No. 508,099

1 Claim.

This invention relates to electrical apparatus and particularly to lead-ins therefor.

In the manufacture of sealed electrical apparatus wherein a metal enclosing vessel is used, I it is desirable that some simple means be provided for leading electrical currents into the inside of such apparatus While insulating such currents from the metal container and preserving the sealed nature of the apparatus. Thus, lo in the case of electric refrigerators of the hermetically sealed type, it is necessary to provide current lead-ins for the compressor motor while -insulating said lead-ins from the enclosing shell and, at the same time, preventing leakage of is the liquid and gases within the shell.

An object of this invention is to devise such a lead-in which will be rugged, cheap and capable of withstanding rough treatment and abuse incidental to quantity production of such .devices n as refrigerators with which said lead-ins are used.

Referring tol the drawing, there is shown a sectional view of a lead-in embodying this invention. A steel shell, having a threaded porl tion as shown, has its inner-surface tapered. Disposed within this shell is a sleeve of ceramic material whose outside surface is tapered to t the inner-surface of the steel shell. This ceramic material may be of porcelain or any of the n well-known materials marketed under various trade-names, such as ,Isolantite 'nie inside of the ceramic sleeve is also tapered. Disposed within the sleeve is a conductor of any suitable material, preferably one having about the same co-emcient of expansion as the ceramic sleeve.

Inasmuch as various conductors, 'having any desired degree of expansion, and suitable for sealing purposes, are on the market, it isunnecessary to further specify the material.

The conductor is preferably provided with a double taper with the thick portion approxi'- mately at the center of the ceramic sleeve. The degree of taper oi' all parts is not important and may be varied. Y

In order to seal the various parts together, a thin layer of glass may be used. If the material is of glass, each one of the various surfaces may be prepared by fusing a thin layer of glass thereon. Thereafter the various elements may be placed in position and strongly heated to cause the various layers of glass to fuse together. If desired, the parts may be assembled while hot to cause fusion.

If cement is used, suitable precautions may be 05 taken to assure tight joints which will be unaiected by the substances coming in contact therewith. Such cementsare well known in the art A seal of this character, having separate and distinct layers of different materials between the conductor and the steel shell, will readily withstand heat and exposure to mechanical and electrical forces. Thus, electrolysis at the junction of the conductor and glass is substantially prevented by the non-uniform nature of the insulation. Furthermore, any cracks in the insulation, especially at the ends cannot travel radially all the way to the metal shell.

A seal of this type may be manufactured 30 very cheaply especially if made in accordance with the method disclosed and claimed in the co-pending application of Godskalk Berge, filed January 12, 1931 serial number 508,149, and assigned to the same assignee as this invention. g5

What I claim is:

A gas-tight current lead-in comprising a metal cylindrical shell having an inner tapered wall, a ceramic sleeve having an outer tapered wall disposed within said shell and extending substantially the entire length thereof, a solid conducting core having a thick central portion tapering down on both sides therefrom disposed within said sleeve and layers of glass joining and sealing opposing surfaces along-substantially the entire length of said shell to form a unitary structure.`

WALKER J. KING. 

